ST. JOHN'S, N.L. - Robert Decker clung to the seat in front of him when the pilot of Cougar Flight 491 called over the helicopter's PA: "Ditching, ditching, ditching!" moments before it hit the North Atlantic.

The lone survivor of the disaster March 12 described the doomed aircraft's last terrifying seconds to an inquiry packed with loved ones of the 17 people who died that day.

"I guess almost as soon as they said 'Ditch' the helicopter lost control," Decker said Thursday in his first detailed public account of the tragedy.

"I was looking out my window for most of it so I knew when we were going to hit the water."

The 28-year-old said the chopper's bow came up slightly and the aircraft turned quickly to its starboard, or right side, just before it crashed about 60 kilometres east of St. John's.

"The next thing I can remember was waking up in a submerged helicopter," Decker said.

"It was instantly filled with water ... it was kind of as if it was sinking the same way it was dropping through the sky."

Decker kept his emotions tightly in check, except for when he fought tears as he thanked the rescuers who saved him.

He has worked since 2006 as a weather and ice observer with Provincial Aerospace. He had flown about 50 times to the three offshore oil sites about 300 kilometres east of St. John's before that ill-fated trip.

Decker had been asleep in a window seat along the starboard of the Sikorsky S-92A. A passenger woke him up just as the pilot announced a mechanical problem that forced the flight to turn back toward land.

He initially didn't think much of it.

It was a cold, clear day that seemed ideal for flying, Decker said. He wasn't supposed to head out until the next day but had received a call the night before asking him to move up his trip because of ice conditions at sea.

Window seats are coveted, and people try to "muscle" to the head of pre-boarding lineups to get them, he told the inquiry.

"Everybody's looking for the most comfortable seats so you don't have to sit next to anyone or the auxiliary fuel tank," Decker said.

He stressed in later testimony that it would have been "next to impossible" for those in seats away from the windows to escape."I just can't see how this person would ever stand a chance," he said, pointing to a rear inside seat on a diagram of the chopper's layout.

There was an auxiliary fuel tank blocking windows on the port, or left side, of the helicopter.

After the crash, the chopper was dimly lit from the glow emitted by the survival suits that each passenger had hastily zipped up in the flight's last moments. The lights are activated by water, Decker said.

Fighting immense water pressure inside the plummeting aircraft, he unbuckled his seatbelt, escaped through the broken window beside him and floated toward the light above.

He managed to inflate a pillow-like flotation collar on his suit to keep his head above water once he broke the surface. But he couldn't get to two lifeboats floating nearby nor fully use his hands because the cold water numbed his fingers.

Trying to swim with a ruptured vertebrae, dislocated ankle and broken sternum "was a losing battle," he said.

Decker remembered worrying that he was paralyzed until he realized he could move his toes. He talked and sang to himself to keep panic at bay, though the fear of internal bleeding gripped him.

Decker had also inhaled sea water, though he doesn't remember fighting for breath.

He recalled seeing a Provincial Aerospace plane flying toward him. At one point he fought panic again as the plane appeared to turn around.

He knew he'd been spotted when the aircraft flew low over him and tipped its wings.

A Cougar search and rescue helicopter arrived later and a basket was lowered. But by then, Decker was hypothermic and could hardly move because of the icy water that had seeped into his survival suit. His body temperature on arrival at a hospital was logged at 28 C, nine degrees below normal.

Rescue swimmer Ian Wheeler, the leader of Cougar's in-house search and rescue team, was lowered into the sea beside Decker, who said he was almost blind and irrational with shock by that point.

Decker thought he recalled Wheeler yelling something about needing to go back for another piece of equipment.

Decker was hoisted into the chopper and rushed to a St. John's hospital where he remained for nearly three weeks.

He said there were long-standing concerns among passengers about survival suits that don't properly fit. And he said the five-day simulated crash training he took in 2006 was inadequate.

"A couple of days of controlled immersion in a pool every few years is not enough to allow anyone to develop the instinctive reactions that they need to have a chance of escaping a helicopter crash like Cougar 491."

He credits his survival to a childhood spent sailing the waters of Conception Bay - and sheer luck.

"Many times I've been thrown into the cold sea water from an overturned boat. I think that experience meant that when the helicopter suddenly filled with icy water I could react instinctively ... it was like a reflex to take a breath and hold it and to stay calm until I could get to the surface," he said.

"I don't think that anyone will ever know why it was that I survived this disaster and the others did not. There probably is no good reason. Just luck."

Decker said he won't fly offshore anymore. But the key to protecting workers who still board choppers everyday lies with the safety of the aircraft, he said.

"Safety starts with the helicopter and I think everything else is secondary."

The inquiry is trying to assess whether the risks of flying to the offshore are as low as is reasonably practical.

Union leader Sheldon Peddle, who represents about 700 offshore workers, said he is confident Cougar is a cautious operator. It's the Sikorsky S-92A he's not sure about.

"With all of the issues that we're seeing, I just hope we don't have another crash," he said.

Sikorsky officials were called this week to inspect the main gearbox of an S-92 to determine what caused a hairline crack on a chopper based in Halifax.

Two international aviation regulatory agencies also recently issued directives that mandate visual inspections of the mounting feet of S-92s after every 10 hours of flight.

The Transportation Safety Board is still probing the crash, but investigators have said that a mounting stud on the filter bowl assembly broke, causing a loss of oil to the main gearbox.